Hi, apologies for not giving enough information relating to this, and thank you for your help.
I tried your solution above but had to remove the 15 from TCP::collect as it would not work with that, I tried some larger numbers but that didn't work either. I am unable to put the config on now as I have to get it cleaned and approved before putting it up. I should hopefully be able to add it tomorrow. The value I am trying to add will actually be added under the CLIENTSSL_CLIENTCERT event but as this would not work I had moved it to CLIENT_ACCEPTED just to eliminate any race conditions that may have been occurring.
The main aim of what I'm trying to do is to get a value I pull from a certificate in iRule one into the session table so I can retrieve it in iRule 2. I have tried numerous times to raise a ticket with F5 but I have not had any reply and no pending tickets show tracked tickets.
The output is below from F5
iRule 1
Oct 15 20:04:28 ip-10-0-0-200 info tmm[9787]: CLIENT_ACCEPTED put 10.0.0.10 with value blocked in blacklist subtable
Oct 15 20:04:28 ip-10-0-0-200 info tmm[9787]: CLIENT_ACCEPTED collect 15 bytes of data
Oct 15 20:04:28 ip-10-0-0-200 info tmm[9787]: CLIENT_DATA found client data
Oct 15 20:04:28 ip-10-0-0-200 info tmm[9787]: CLIENT_DATA send to virtual vs-test-02
Oct 15 20:04:28 ip-10-0-0-200 info tmm[9787]: send to virtual vs-test-02
Oct 15 20:04:28 ip-10-0-0-200 info tmm[9787]: result is blocked
iRule 2
Oct 15 20:04:28 ip-10-0-0-200 info tmm[9787]: CLIENT_ACCEPTED result for 10.0.0.10 is .